


puberty is nature's dump truck: hot, fast, and full of garbage

by WithAWhisper



Category: Undertale (Video Game)
Genre: Alternate Universe - Swapfell, F/M, Sexual Fantasy, Vaginal Fingering, first time sexual experience, how is that not a tag yet
Language: English
Status: Completed
Published: 2017-10-03
Updated: 2017-10-03
Packaged: 2019-01-08 18:30:22
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,745
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12259764
Author URL: https://archiveofourown.org/users/WithAWhisper/pseuds/WithAWhisper
Summary: Rus makes sure your first sexual experience comes with a bang.





	puberty is nature's dump truck: hot, fast, and full of garbage

**Author's Note:**

> -Throws at- Here, have this.

“so...you’re curious about sex.” 

Here you are, with your bonefriend in his bed. But not in a sexy way. At least, it didn’t start that way. You couldn’t sleep and neither could he, so here you both are after you blurted out the first thing that came to mind.

“Yeah.” You’re not exactly blushing about it. It wasn’t anything to blush about in the first place, Rus already knew you were a virgin.

But you were also asexual.

You’ve been friends with Rus a lot longer than you were in a relationship together and you already knew about his, ahem, proclivities. Just as he knew you didn’t feel sexual attraction towards people. Rus had quite the sexual appetite, and at the time you wondered if maybe that would be something that put a wrench in your relationship. But when you got together, he never gave you shit for it and never pressured you.

In fact, his exact words after you confessed your worries was “i got a good pair of hands to take care of myself, darlin’.” and then he tapped his fangs to your forehead and pulled you to his chest.

And that made you blush.

Anyway.

“It’s just been a thing in my head for awhile now.” You try to explain.

“is it now?” He says, amusement in his tone. You don’t have to look at him to know he’s smirking.

“Shuddup.”

Rus shifts as he props himself up against his headboard. You were lying on your side pressed against him, head on his ribcage, so you shift to accommodate him moving and look up. He’s looking down at you, and you quickly duck your head.

It first came about when you were up in bed, not tired, at 1 am and you had nothing to do so. Down went your pants and your hand goes to town. Masturbating wasn’t something that you did often, it felt good and nice but in the same way that scratching an itch would feel good and nice. And an orgasm later you usually felt tired enough to slip away into sleep.

And while you were, yanno, flicking the bean your thoughts turned to Rus. And it occurred to you that, hey, he probably jerked off to the thought of you. A thought that you were kinda into, considering you felt heat bolt up and down your spine all the way to the spot between your legs where your hand was. You wondered whether he sat on his bed, pants unbuttoned and shirt up as he touched at his bones, his ribs, spine. You’ve seen his tongue, orange and long. (You’ve tasted it too.) You wonder if his magic extended to other parts.

And while you were so busy thinking about your boyfriend, touching himself to the thought of you, your hand was still going and going until you just. Came. Seized you and threw you over the edge and left you breathless and gasping. You never had an orgasm that strong before.

And after that, now whenever you two are together like this, you’ve been...restless. Not always, but when you kiss and it gets close to a makeout session, or you’re pressed up together on the couch watching tv, or here lying in bed. You’re pretty sure the only accurate word to call it is horny.

“you want to?”

You snap out your thoughts. “Huh?” You say, dumbly. 

He grins, his single golden fang glinting in the dark of his room and reaches a hand up to tuck your hair behind your ear. You make a face at him and he huffs out a laugh, a soft and low ‘heh’.

“wanna have sex?” He explains.

Right now? Just like that? But you’re in your pajamas. You’re not sexy. Your underwear is green and has frogs and lilypads on them.

Rus sees the look on your face and he shrugs and makes to settle down. “it’s fine if you don’t, but since you were wondering i thought i’d offer. if not…”

“I’m- I don’t mind. I mean, I want to!” You blurt. Fuck it, go for broke. “But I wouldn’t know what to do.”

“we don’t have to have full on sex. it can go slow.” He looks so calm while speaking. You’re a bit jealous about that, because you’re starting to heat up and it’s not because you’re horny. (Well, you think you kinda are but still)

“Really?”

“sugar, if you say stop, we stop. if you don’t like it then you don’t like it. i’m not gonna force you into anything you won’t like.”

Ugh, your bonefriend is wonderful. You’re blushing.

“Okay.”

You feel more than see Rus shift down and then a bony hand is cupping your chin and tilting your head up pulling you in for a kiss. Okay kissing. You can do kissing. Your hands were already resting on his jacket that he hadn’t bothered to take off so you clench your hands into the fabric and hold on.

He breaks away, looking affectionate and soft and ugh. You bury your face into his jacket and he laughs. Fucker.

“ever touched yourself?” He asks into your hair, his arm wrapped around you a lot more apparent. His body in contact with yours, a lot more apparent.

“Y-yes.” You stutter. “Sometimes.”

Rus sits up a little more and draws you into his lap, between his legs so your back pressed into his rib cage.

“help me along sugar, show me how you do it.” Rus rumbles, doing shit with his voice as he grabs one of your hands to direct it to your crotch.

Fuck. Okay.

You dip your hand into your sweatpants and (froggy) underwear and just set your hand against your mound. You’re horny(maybe) but you’re definitely not aroused, you’re not wet so you just touch at the skin around your clit, too dry to properly stimulate it directly without chafing.

“what do you think about?” He rumbles into your ear and fuck him, that shit always gets to you.

“Nothing really. I didn’t think about much before.” You hunch down to get away from his voice but he only dips down and presses his chin into your shoulder. Damnit.

“didn’t before? what changed, hun.” Of course he’d catch that. Not a lot got pass Rus.

You mumble that maybe, sorta, kinda, you jerked off your lady boner to your skeleton boyfriend getting off to the thought of you. 

“come again?” he says and taps his fangs to your cheek when you groan and whine. “sorry you’re gonna have to speak louder than that.”

“Mood’s gone, don’t pass go, don’t collect- mmph.” Oh, kissing again. He can’t always kiss you to distract you and one of these days it won’t work. One of these days.

You take the opportunity to continue with your touching. While Rus kisses you, he starts running his hands up and down your sides, under your shirt. Up, bones on your ribs and the band of your bra and down to the hem of your sweats. It felt nice.

You also think it might be working. Where your hand was working was starting to feel good. You pull away from the kiss when you feel another hand, bigger and bonier, slide down and envelope yours, stopping your movement. Another hand joins the second only it’s tugging at the band of your sweats and pulls down, underwear with. You squeak.

“off.” Rus says and his voice is different, before when he was only teasing you it sounded more like a purr. This time it was a growl. A command.

You would fight back, make sass normally but you lift your hips and down your clothes went, tangled up together around your knees until you kick the fabric off. Modestly, you keep your legs closed but Rus hooks a palm under your knee and keeps you wide open, to your embarrassment.

“lemme see.” And then the hand covering yours over your clit pushes your hand aside and- wowie, yup, that’s a skeleton hand at your crotch. He strokes his middle finger and third into your folds, into your gathered slick and over your clit, rubbing his thumb over the hood and you jerk your hips and gasp, _fuck._

“yeah, i think about you. i thought about you _before_ we were even together.” he says, as he began to fingerfuck you and you choke on your breath. “i thought about you this morning when you stretched and your shirt rode up, your skin looked so damn soft and you looked so sweet and open and _vulnerable_.” 

You could feel his chest rattle and vibrate with the low registers his voice was reaching but you could barely focus on that with the blood rushing through your ears. 

His other hand joins in the fun and you’re left gripping onto his arms and breathing heavily, making small whimpering noises.

Then his fingers crook deep, deeper than you could ever reach with your own hands and the fingers of his other hand presses into your clit full on and your hips convulse and you clamp your legs around his hand hard. He presses his teeth to your cheek 

“there you go, there you go,” he hushes you and you realize you’re keening, high in your throat and you never do that, never made much noise as you touched yourself. It’s not a tease, Rus doesn’t linger with soft touches, just pulls you along the pump of his phalanges inside you and the rasp of his low voice in your ears.

You cum. Your back arches and your whole body clenches and all the while, Rus’ hands guide you through your orgasm until you have to squirm uncomfortably and bat your hands uselessly against his arms.

He pulls his fingers out with an obscene slick motion and you can’t even be bothered to feel embarrassed about it. 

“damn. nearly took my hand off with how hard you clenched your legs.” he laughs in your ear. You reach up and bat at his face but he takes your hand and presses his fangs to your knuckles.

“...D’you want me to...?” You’re becoming aware of a glow at the corner of your eye. Lower down, in your lap. Behind you.

“...i wouldn’t say no, but you don’t gotta-” Rus hitches a breath when you reach down, unseeingly and cup the bulge that _does_ indeed exist.

“Gimme a couple minutes to get myself together.”

**Author's Note:**

> Reader's first time is how I imagine my first time to be actually.
> 
> Hot, fast and I'm full of garbage.


End file.
